Collodion coating composition



Patented Sept. 4, 1928.

UNITED STATES PATENT OFFICE.

WILLIAM HENRY GARDNER, OF LOS ANGELES, CALIFORNIA, ASSIGNOB- OFONE-FOURTH 1'0 CLARENCE NEIL DE WITT, OF LOS ANGELES, CALIFORNIA.

COLLODION COATING COMPOSITION.

No Drawing.

This invention relates to compositions of matter adapted for use as asolution in which gelatinous articles such as developed photographicfilms or plates, either posi- 5 tive or ne ative, may be immersed, forthe purpose 0 giving many added features, including longer life, to suchimmersed article thereby providing a-new article of manufacture. For thesake of brevity the word film .only will be hereinafter used throughoutthe specification and claim, to mean a film having a celluloid baseprovided with a sensitized surface, or a plate having a glass baseprovided with a sensitized surface; it

being understood that film having a celluloid base may be either inlarge rolls such as motion picture film, or in small rolls such a isused in kodaks, or in small sheets such as after the larger or smallrolls have been cut into individual pictures, or as is used in filmpacks.

For some purposes it may be practicable to treat only the side of thefilm base opposite that of the sensitized surface. How ever thisinvention relates more particularly to treating both sides of film afterit has been developed and such film will be designated in thisapplication as developed film which may be either positive or negative.

An object of this invention is to provide for gelatinous articles, suchas developed films, a waterproof protector and preserva= tive that isflexible and that will not chip or crack under rough handling, or normaltemperature changes:

Other objects and advantages are cheapness, ease of'handling and ease ofapplication.-

40 An' object is to provide developed motion picture films with atransparent coating which will retard the explosion point of such films.I

An object is to provide means whereby a 4 developed film may be cleanedor washed with any suitable kind of liquid cleaning preparation.

Another object is to provide novel means whereby the ratchet teeth holesin motion pictpre films may be materially strengthene i Advantagesgained by immersing devel.

Application filed June 23, 1924. Serial No. 721,935.

oped films or like gelatinous substances in my solution are It clearsthe picture or negative and brings out the detail.

Prevents injury to such film by any liquid.

Makes the celluloid base film very flexible so that sharp bending willnot crease or crack such film.

The gelatine on the film will not swell after applying my solution.

lieduces tendency of developed film to our Retards the explosion pointof film.

Another advantage is that oil or water colored developed film may betreated with equal advantages and without danger of the colors runningduring application orimpairment of color after drying.

A further object is to provide novel means whereby the developedsensitized surface of a film may be covered or coated with a transparentcoating so that such surface will be protected and preserved and not beexposed to the dangers of handling.

This invention is broadly new, basic and pioneer in that I provide adeveloped film "with a transparent protective and preservative coating.

Other objects, advantages and features of invention may appear from thesubjoined detail description and the appended claim.

A well known type of developed film comprises a base or body, having onone side pf said body a developed sensitized surace.

In the film the body is of celluloid and is provided with ratchet teethholes that are adapted to receive the usual ratchet teeth of aprojecting machine feeding mechanism.

This invention resides mainly in covering the developed sensitizedsurface with a covering or coating. But by completely covering thedeveloped film, the bodyand surface are protected as well as providingmeans for strengthening the ratchet teeth holes the walls of which arecompletely covered by the coating. It is found in practice that many ofthe holes may be spanned by a pellicle of the solution which may beeasily cleaned out by running the film through the regular feedingmechanism on a projecting machine.

' by first mixing together a solution or composition of matterconsisting of varnish preferably Spar varnish), ether, japan rier,Venice turpentine, (an oleoresin of the European larch) and collodion inthe manner and proportions substantially as follows, to wit:

Varnish (of the character of Spar varnish 1 pint; Ether 4 pint; Japandrier 1 ounce; Venice turpentine 1 ounce; Collodion 2 ounces;

and then dipping a developed film in such solution.

The above ingredients may be thoroughly mixed together in any order, but'for the sake of convenience and speed in mixin the following order andmethod is pre ered. The varnish is thinned with the ether which makes itracticable to use a varnish on the film, the apan drier is then added,the Venice turpentme, is heated until it is of a consistencycorresponding to that of a thin cough syru and is then added to themixture, and t en the collodion is added.

By heating or melting the Venice turpentine it willmix more readily andevenly with the other ingredients.

It is very im ortant to use only the. correct amount 0 Venice turpentineas too large an amount will prevent drying of the solution.

The Venice turpentine and the collodion gives to the product thatcharacteristic which prevents chipping of the coating applied to thefilm.

I have found by experiment that a satisfactory product or solution.Inay' be obtained by eliminating the""collodionfand' also by omittingthe ether and using a proportionate amount of collodion in substitutetherefor. However, the preferred and most satisfactory solution includesall of the ingredients as above set forth.

After the ingredients are all added tother. the solution is shaken'tothoroughly mtermingle the ingredients with one an other when thesolution may be ut in containers and tightly corked, when it will, keeppracticall indefinitely.

The so ution is preferably added to the film by dipping the film intothe solution which may be contained in a pan or tank havin an open top.The film is run through the solution or washed therein in a mannersimilar to that used when the film is (level 0 ed, one gallon of thesolution will coat 21 out 5000 feet of developed motion picture Greatcare must be taken that the developed film does not touch any exposedpart 0 the container above the solution or any other article whenapplying the solution or until it is thoroughly dried. In case the filmshould touch the edge of the pan or tank containing the solution or anyother article while wet with the solution the film will turn a mil whiteand that ortion of the developed lm will be ruin After dipping orrunning the developed film into or through the solution it is then hungup to dry in any suitable manner such as-commonl used after developingof the film. It wi 1 take about 30 minutes for the coatin or solution todry.

If t e film is supported from both ends in a horizontal POSltlOIl duringdrying any puddles of the solution accumulating on the developed filmwill not be detrimental to it. The only result will be that the coatingat such laces will be thicker.

I c aim:

A film protector and preservative solution composed of the followingingredients in. the proportions substantially as set forth, namely; onepint of Spar varnish; one quarter pint of ether; one ounce japan drier,one ounce Venice turpentine, and two ounces of collodion.

Intestimon whereof, I have hereunto set my hand at 0s Angeles,California, this 16th day of June, 1924.

- WILLIAM HENRY GARDNER.

